Audio Compression

Can anyone here offer me some advice on what is the standard audio codec to use with DivX.

Here is my situation:
I have used Premiere to edit my home video (via DV Cam). I want to have a DivX copy on my machine for backup and to give to friends. Right not 60 min w/ DivX 5.0 codec (at 100%) and no audio compression gives me a 1.6GB file size. Any suggestions? I have some DivX movies that are over any hour and are under 700MB. Keep in mind that I'm using Premiere to export to DivX (via Plug-in)